:root {
    --inverted-corners-background: #52525b;
    --inverted-corners-size: 2rem;
}

.inverted-corners {
    background-color: var(--inverted-corners-background);

    /* Used to position the corner */
    position: relative;

    /* Misc */
    height: 100%;
}

.inverted-corners::before {
    content: '';

    /* Absolute position */
    bottom: calc(-2 * var(--inverted-corners-size));
    left: 0;
    position: absolute;

    /* Size */
    height: calc(2 * var(--inverted-corners-size));
    width: var(--inverted-corners-size);

    /* Border */
    background-color: transparent;
    border-top-left-radius: var(--inverted-corners-size);
    box-shadow: var(--inverted-corners-background) 0px calc(-1 * var(--inverted-corners-size)) 0px 0px;
}

/* Use case */
.inverted-corners--speech {
    /* Border radius */
    border-bottom-right-radius: var(--inverted-corners-size);
    border-top-left-radius: var(--inverted-corners-size);
    border-top-right-radius: var(--inverted-corners-size);

    /* Center the content */
    align-items: center;
    display: flex;
    justify-content: center;

    /* Misc */
    color: #fff;
}
